title: Jasmonate: A decision maker between cell death and acclimation in the response of plants to singlet oxygen.
abstract: Under stress conditions that bring about excessive absorption of light energy in the chloroplasts, the formation of singlet oxygen ( (1)O2) can be strongly enhanced, triggering programmed cell death. However, the (1)O2 signaling pathway can also lead to acclimation to photooxidative stress, when (1)O2 is produced in relatively low amounts. This acclimatory response is associated with a strong downregulation of the jasmonate biosynthesis pathway and the maintenance of low jasmonate levels, even under high light stress conditions that normally induce jasmonate synthesis. These findings suggest a central role for this phytohormone in the orientation of the (1)O2 signaling pathway toward cell death or acclimation. This conclusion is confirmed here in an Arabidopsis double mutant obtained by crossing the (1)O2-overproducing mutant ch1 and the jasmonate-deficient mutant dde2. This double mutant was found to be constitutively resistant to (1)O2 stress and to display a strongly stimulated growth rate compared with the single ch1 mutant. However, the involvement of other phytohormones, such as ethylene, cannot be excluded.
authors.affiliation: Institut de Microbiologie de la Méditerranée; Laboratoire de Chimie Bactérienne; CNRS- UMR7283; Marseille, France.
authors.forename: Fanny
authors.initials: F
authors.lastname: Ramel
authors.affiliation: CEA; DSV; IBEB; Laboratoire d'Ecophysiologie Moléculaire des Plantes; Saint-Paul-lez-Durance, France; CNRS; UMR 7265 Biologie Végétale et Microbiologie Environnementales; Saint-Paul-lez-Durance, France; Aix-Marseille Université; Saint-Paul-lez-Durance, France.
authors.forename: Brigitte
authors.initials: B
authors.lastname: Ksas
authors.affiliation: CEA; DSV; IBEB; Laboratoire d'Ecophysiologie Moléculaire des Plantes; Saint-Paul-lez-Durance, France; CNRS; UMR 7265 Biologie Végétale et Microbiologie Environnementales; Saint-Paul-lez-Durance, France; Aix-Marseille Université; Saint-Paul-lez-Durance, France.
authors.forename: Michel
authors.initials: M
authors.lastname: Havaux
mesh_terms: D000064:Acclimatization / Q000187:drug effects* / Q000528:radiation effects; D017360:Arabidopsis / Q000166:cytology* / Q000187:drug effects / Q000502:physiology* / Q000528:radiation effects; D016923:Cell Death / Q000187:drug effects / Q000528:radiation effects; D003517:Cyclopentanes / Q000378:metabolism*; D008027:Light; D009154:Mutation / Q000235:genetics; D018384:Oxidative Stress / Q000187:drug effects / Q000528:radiation effects; D054883:Oxylipins / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects / Q000528:radiation effects; D026082:Singlet Oxygen / Q000494:pharmacology*
chemical_list: D003517:Cyclopentanes; D054883:Oxylipins; D026082:Singlet Oxygen; C011006:jasmonic acid
keywords: 1O2 acclimation; ch1mutant; high light; jasmonate; phytohormone signaling